Flight decks in an aircraft need to be secured against access of unauthorized persons. Thus, flight deck doors of aircraft are usually reinforced to prevent or at least delay passage through the door by persons other than the flight deck crew. A cockpit door locking system (CDLS) is provided to control the closing, locking and opening of the flight deck door from the inside of the flight deck so that only flight deck personnel are able to control the opening and closing state of the door.
In some instances, specifically when the flight deck by itself does not include separate facilities that the flight deck crew needs to use at some times, such as for example a separate lavatory, a member of the flight deck crew will open the flight deck door to leave the flight deck area in order to use the lavatory provided for the remaining persons on board of the aircraft. During the leave or absence of the flight deck crew member cabin, security measures have to be put in place in order to ensure flight deck safety and protection against unwarranted intrusion into the cockpit by unauthorized persons.
Some prior art solutions aim at allowing unfettered secure access to a lavatory by the flight deck crew. Document DE 102 04 544 A1 for example discloses a revolving gate rotatably mounted in a stationary gate frame to control ingress to and egress from an access restricted compartment, such as the cockpit in an aircraft. The revolving gate is rotatable about its central longitudinal axis through angular sectors to bring the gate opening into alignment with any one opening of at least two frame openings at a time, with the status of the revolving gate being controllable from the cockpit for incapacitating any unauthorized intruder.
Document US 2009/0065641 A1 discloses a multi-position door system for an aircraft with a flight deck door hingedly coupled to a flight deck bulkhead. A lavatory is adjacent to the flight deck bulkhead and formed of a lavatory bulkhead. A lavatory door is coupled to the lavatory bulkhead. A latching mechanism is attached to the flight deck door. The latching mechanism in a first position engages the flight deck bulkhead and in a second position engages the lavatory bulkhead.
There is, however, a need for improvements in security door systems for aircraft which are easier to install and more convenient in operation.